On Fri, 23 Sep 2005 19:13:50 +0530 Panthini <panthini.pandit@xxxxxxxxxxxxxx> wrote: > Following is the screenshot of compilation process: > [root@localhost root]# gcc -Wall -O2 -D__KERNEL__ -DMODULE > -I/usr/src/linux-2.4.21-27.EL/include/ hello.c > > /usr/lib/gcc-lib/i386-redhat-linux/3.2.3/../../../crt1.o(.text+0x18): > In function `_start': > : undefined reference to `main' > collect2: ld returned 1 exit status > [root@localhost root]# > /***************************************/ > why this is referring to 'main' even though I have not written any > main() function in hello.c. gcc automatically links agains libc & libgcc unless instructed not to do it (-nostdlib). Alternatively, you could link with ld instead of gcc. But building modules that way (with your own compiler command line & options) is strongly discouraged. You should use the kernel build system even when building external modules. See http://lwn.net/Articles/21823/ for details, most of it applies to recent 2.4 kernels too. Here's a simple makefile that works for me on AS 3.0: ######################################### O_TARGET := hello_module.o obj-y := hello.o obj-m := $(O_TARGET) include $(TOPDIR)/Rules.make ######################################### Then you can build with the following command: make -C /lib/modules/`uname -r`/build modules SUBDIRS=`pwd` -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
